Shearing device for unextruded butts in an indirect metal extrusion machine

ABSTRACT

In an indirect metal extrusion machine butts of a billet left on the end surface of a die are sheared off the die by a cutter arranged on a frame over the die when the die is retracted after the extrusion of the billet is completed.

United States Patent [191 Kishinn et a1.

[ SHEARING DEVICE FOR UNEXTRUDED BUTTS IN AN INDHRECT METAL EXTRUSKONMACHINE [75] Inventors: Shunji Kishino; Takahiro Abe, both of Muroran;Reishi Tamara, Noboribetsu, all of Japan [73] Assignee: Japan SteelWorks Ltd., Tokyo,

Japan 22 Filed: 0ct.31, 1972 211 App]. No.: 302,506

[30] Foreign Application Priority Data Nov. 25, 1971 Japan 1. 46-94134[52] US. Cl. 72/255, 72/462 [51] Int. Cl. B2lc 23/00 [58] Field ofSearch 72/255, 254, 467, 462

[in 3,827,273 [451 Aug. 6, 1974 [56] References Cited UNITED STATESPATENTS 2,456,856 12/1948 Bath 72/462 3,220,237 1 H1965 Govan 72/2553,357,226 12/1967 Snell 72/253 3,407,642 10/ 1 968 3,522,721 8/1970Whiting .11. 72/255 Primary Examiner-Charles W. Lanham AssistantExaminer--Robert M. Rogers Attorney, Agent, or Firm-Wenderoth, Lind &Ponack [5 7] ABSTRACT In an indirect metal extrusion machine butts of abillet left on the end surface of a die are sheared off the die by acutter arranged on a frame over the die when the die is retracted afterthe extrusion of the billet is completed.

1 Claim, 5 Drawing Figures PATENTEU RUB 51974 SHEU 1 (IF 2 I PRIOR ARTFIG. 2

PRIOR ART SHEARING DEVICE FOR UNEXTRUDED BUTTS IN AN INDIRECT METALEXTRUSION MACHINE BACKGROUND OF THE INVENTION This invention relates toan indirect metal extrusion machine, and more particularly to a shearingdevice which can cut off unextruded butts with safety and reliability atthe completion of extrusion when a metal is extruded by indirectextrusion.

Hitherto when a metal is extruded by indirect extrusion, a die forextrusion is fitted on the end of a long hollow stem and the unextrudedbutt which is stuck to the die must be removed at the completion ofextrusion.

FIG. 1 shows a die mounting device in which a die 1 is simply insertedin the axial direction as an example of conventional method of removingbutts.

In this case the extruded product is cut off with a shearing tool 4between the die 1 and the stem 2 after the die 1 is slightly moved awayfrom stem 2 to permit the shearing operation.

By this method, however, in order to remove the unextruded butt stuck tothe die 1, the die 1 must be taken out of the extruding machine and thebutt must be separator with a specially provided butt separater, andthereafter the die must be remounted on the stem manually ormechanically for the next succeeding extrusion.

To mount the die in this way at every operation, much labor is needed inthe case of manual operation, causing a poor productivity, and formechanical operation a die setting device must be provided to operate along arm having a die grip device from outside the machine. In additiona butt separater is needed and these requirement cause disadvantages incost and maintenance of the apparatus.

In FIG. 2 showing another example of removing method, because the dieremains fixed to the stem, shearing is executed inside the machinewithout exchange of dies every time.

In this case the butt shear 6 is mounted on an upper tie-rod 7 of themachine and the shearing tool 4a cuts off the butt with a highefficiency. But the reaction force from the shearing tool 4a acts at theend of the long hollow stem and the center of the tie-rod, causing a bigbending moment which is unfavorable from the standpoint of strength ofthe machine.

One of the reasons why the indirect extruding machine has not been usedin general, although the indirect extruding method has more advantagesin principle than the direct method commonly used, is the process ofcutting the butt when the die is at the extruding position or supportedon the stem in the center space of the machine.

SUMMARY OF THE INVENTION It is an object of the present invention toeliminate the disadvantages of conventional types of indirect extrusionmachines and to provide a butt shearing device which will make itpossible to cut off the butt stuck on the die fixed at the end of a longstem reliably and with a reasonably simple device. The shearing deviceof the present invention is preferably composed of a butt cutting meansslidably mounted on a platen of an indirect metal cutting machine and adie supporting means which cooperates with the cutting means.

BRIEF DESCRIPTION OF THE DRAWINGS This and other objects of the presentinvention will become more apparent to those skilled in the art whenconsidered in reference to the following detailed description in thelight of the accompanying drawings, wherein:

FIG. 1 is a sectional view of an example of a conventional butt removingmethod;

FIG. 2 is a sectional view of another example of a conventional buttremoving method;

FIG. 3 is a view in section of an embodiment of the device according tothe present invention at the completion of extrusion;

FIG. 4 shows an enlarged side view of the device shown in FIG. 3; and

FIG. 5 shows a view in vertical section of the device shown in FIGS. 3and 4 in the position for shearing a butt.

DESCRIPTION OF THE PREFERRED EMBODIMENT In FIG. 3 which shows anembodiment of the device according to the present invention, partly insection, at the time of completion of extrusion, the die 11 is fixed tothe stem 12 and the extruded product 13 is extruded through the hollowof the stem 12.

The reference numeral 14 represents a shearing tool for the unextrudedbutt stuck to the die 11 and is fixed to a butt shearing head 16.

The shearing head is mounted so as to be freely movable up and down on aframe 17 fixed to the platen 24.

The reference numeral 18 represents a stem holder, holding the stem 12on the end surface thereof and the stem 12 is fixed to the stem holderby a stem clamp 19.

As shown in FIG. 4, a pair of die holders 20 is mounted on the frame 17and an upper horizontally movable pressure bearing plate 21 with a lowertapered edge is set beneath the die holder 20 and another pressurebearing plate 22 with an upper tapered edge complementary to the taperededge on upper plate 21 and engaged therewith is fixed on the frame 17.

The movable bearing plate 21 can slide by means of adjust bolts 23 onthe frame 17 in order to adjusting the height of the die holder 20.

As shown in FIG. 3, cutting line A of the shearing tool 14 must be insuch a position as to traverse the stem 12.

The movement of the stem 12 in the axial direction thereof is executedby opening and closing of a gate (not shown) mounted on the platen 24generally called a gate lock mechanism.

In this embodiment, the frame 17 for the butt shearing head has aunitary body construction, in which the die holding device is set, butthe die holding device can be mounted on the platen 24 as separatepieces.

It is most desirable that the position of butt shearing head 16 coincidewith the position for the case of direct extrusion.

Following is an explanation of the butt shearing operation with thedevice according to the invention.

The die 11 and the stem 12 are moved to the position of cutting line Afor the shearing tool 14 of the butt shearing head 16 on the frame 17mounted on the platen 24 shown in FIG. 5 from the position at thecompletion of extrusion shown in FIG. 3. At this position the die 11 isheld and fixed around its outside by the die holder 20.

The shearing head 16 slides downward on the slide 17 and cuts off thebutt with the shearing tool 14 at the position of cutting line A. Duringthis operation, the reaction force on the shearing tool 14 istransmitted to the frame 17 by means of the pressure bearing plates 21and 22.

As above described, exchange of dies for every extrusion is not neededand the die setting device can be eliminated. Moreover structurallyundesirable large bending moments do not occur on the long stem and thetie-rod.

As the position of butt shearing coincides with the position in case ofdirect extrusion and one butt shearing device can be used for bothdirect and indirect extrusion, the structure of the extruding machinecan be simplified, giving another advantage.

While the invention has been shown and described with reference to apreferred embodiment thereof it will be apparent that other changes andmodifications can be made in the present invention and therefore it isunderstood that all changes, equivalents, and modifications within thespirit and scope of the present invention are here meant to be includedin the appended claims.

What is claimed is:

1. In an indirect metal extrusion machine having a platen and a dieholding stern mounted in a stem holder and held therein by a stem clampand movable through the platen in the direction of the length of thestem so that the die is projected from the platen, an improved buttshear means comprising a frame mounted directly on the platen above thestem, a butt shear slidably mounted on said frame for slidable movementacross the end of the die when the stem is withdrawn into the platen,said frame extending down and around the stem, and an upper and lowerdie holder mounted in the portion of said frame which extends downaround the stem and engaging the die for holding the die when the stemis withdrawn into the platen.

1. In an indirect metal extrusion machine having a platen and a dieholding stem mounted in a stem holder and held therein by a stem clampand movable through the platen in the direction of the length of thestem so that the die is projected from the platen, an improved buttshear means comprising a frame mounted directly on the platen above thestem, a butt shear slidably mounted on said frame for slidable movementacross the end of the die when the stem is withdrawn into the platen,said frame extending down and around the stem, and an upper and lowerdie holder mounted in the portion of said frame which extends downaround the stem and engaging the die for holding the die when the stemis withdrawn into the platen.